This invention relates to explosives and more particularly to that branch of explosives known as propellants wherein the propellants are those stabilized and densified with at least one lead fluoride.
In the explosive field there are four general subdivisions -(1) primary explosives (2) secondary explosives, (3) pyrotechnics, and (4) propellants. The primary explosives are generally very sensitive and serve to initiate a other less sensitive explosives. A secondary explosive has high brisance and shattering power but little propelling power. Most secondary explosives are usually less sensitive than primary explosives and require a primary explosive to initiate them. Pyrotechnics burns to produce visible smoke or provide light. Propellants, which are embodied in this invention, are designed to produce a large quantity of gas quickly to provide a propelling or driving force for shells or rockets.
The development of a useful propellant requires that many characteristics of the propellant be balance. Some critical characteristics of a propellant are density, stability, and combustion efficiency. High density is usually desirable for a propellant because systems in which a propellant is used are generally limited in volume. A greater weight of a high density propellant is, therefore, preferred for use in a volume-limited system. A comparison of the thrust per pound of different propellants considered in relation to the volume and density of each gives an indication of the performance of the propellant. Also, the propellant must burn substantially completely in order to make best use of the propellant. For example, standard high-energy propellants contain aluminum which must completely oxidize for highest energy production. However, the aluminum in a propellant rarely provides close to 100% of the available energy due to its failure to undergo complete oxidation the aluminum.
Lead or lead compounds are a possible solution to the density problems. However, lead compounds and lead create other problems because of incompatibility with other propellant components. Thus, use of lead containing materials to provide high density fuels for propellants is not known at this time to be feasible.
Stability is another critical characteristic of a propellant. A propellant, for military purposes, must maintain its thrust, power, and physical characteristics over a temperature range of -65.degree. F. to 165.degree. F. (approximately -54.degree. C. to 74.degree. C.). Double base and composite modified double base propellants have an additional stability problem. These propellants are susceptible to the formation of internal gases with aging. The gases thus formed cause cracking of the propellant and destruction of the physical properties of the propellant.